feat: added CreateTableIfNotExists

bob.go

@@ -15,6 +15,10 @@ func (b BobBuilderType) CreateTable(table string) CreateBuilder {
 	return CreateBuilder(b).Name(table)
 }
 
+func (b BobBuilderType) CreateTableIfNotExists(table string) CreateBuilder {
+	return CreateBuilder(b).Name(table).IfNotExists()
+}
+
 // HasTable checks if a table exists with HasBuilder interface
 func (b BobBuilderType) HasTable(table string) HasBuilder {
 	return HasBuilder(b).HasTable(table)
@@ -33,6 +37,11 @@ func CreateTable(table string) CreateBuilder {
 	return BobStmtBuilder.CreateTable(table)
 }
 
+// CreateTableIfNotExists creates a table with CreateBuilder interface, if the table doesn't exists
+func CreateTableIfNotExists(table string) CreateBuilder {
+	return BobStmtBuilder.CreateTableIfNotExists(table)
+}
+
 // HasTable checks if a table exists with HasBuilder interface
 func HasTable(table string) HasBuilder {
 	return BobStmtBuilder.HasTable(table)

create.go

@@ -12,13 +12,14 @@ import (
 type CreateBuilder builder.Builder
 
 type createData struct {
-	TableName string
-	Schema    string
-	Columns   []string
-	Types     []string
-	Primary   string
-	Unique    string
-	NotNull   []string
+	TableName   string
+	IfNotExists bool
+	Schema      string
+	Columns     []string
+	Types       []string
+	Primary     string
+	Unique      string
+	NotNull     []string
 }
 
 func init() {
@@ -30,6 +31,11 @@ func (b CreateBuilder) Name(name string) CreateBuilder {
 	return builder.Set(b, "TableName", name).(CreateBuilder)
 }
 
+// IfNotExists adds IF NOT EXISTS to the query
+func (b CreateBuilder) IfNotExists() CreateBuilder {
+	return builder.Set(b, "IfNotExists", true).(CreateBuilder)
+}
+
 // WithSchema specifies the schema to be used when using the schema-building commands.
 func (b CreateBuilder) WithSchema(name string) CreateBuilder {
 	return builder.Set(b, "Schema", name).(CreateBuilder)
@@ -77,6 +83,10 @@ func (d *createData) ToSQL() (sqlStr string, args []interface{}, err error) {
 
 	sql.WriteString("CREATE TABLE ")
 
+	if d.IfNotExists {
+		sql.WriteString("IF NOT EXISTS ")
+	}
+
 	if d.Schema != "" {
 		sql.WriteString("\"" + d.Schema + "\".")
 	}

create_test.go

@@ -75,4 +75,15 @@ func TestCreate(t *testing.T) {
 			t.Fatal("should throw an error, it didn't:", err.Error())
 		}
 	})
+
+	t.Run("should emit create if not exists", func(t *testing.T) {
+		sql, _, err := bob.CreateTableIfNotExists("users").Columns("name").Types("text").ToSQL()
+		if err != nil {
+			t.Fatal(err.Error())
+		}
+		result := "CREATE TABLE IF NOT EXISTS \"users\" (\"name\" text);"
+		if sql != result {
+			t.Fatal("sql is not equal to result: ", sql)
+		}
+	})
 }

has.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"errors"
 
+	"github.com/aldy505/bob/util"
 	"github.com/lann/builder"
 )
 
@@ -71,6 +72,6 @@ func (d *hasData) ToSQL() (sqlStr string, args []interface{}, err error) {
 	}
 
 	sqlStr = ReplacePlaceholder(sql.String(), d.Placeholder)
-	args = createArgs(d.Name, d.Column, d.Schema)
+	args = util.CreateArgs(d.Name, d.Column, d.Schema)
 	return
 }